Devices in sheet bending machines



P. S. V. LINDM'ARK DEVICES IN SHEET BENDING MACHINES Jan. 20, 1970 2 Sheets-Sheet 2 Filed June 25, 1967 R m w w m United States Patent 3,490,260 DEVICES IN SHEET BENDING MACHINES Per Samme Valentin Lindmark, Pilgatan 1, Lulea, Sweden Filed June 23, 1967, Ser. No. 648,327 Claims priority, application Great Britain, Nov. 23, 1966, 52,433/ 66 Int. Cl. B21d 5/14, 9/10; B21b 31/10 U.S. Cl. 72-169 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to sheet bending machines and more particularly to a device in a sheet bending machine having at least two rotatable and co-operative rollers, preferably an upper roller and at least one lower roller for allowing a round-bending of a piece of sheet material introduced between said rollers.

In machines of this kind relatively coarse sheet workpieces often are rounded or bent so far as they enclose more or less completely one of the rollers, preferably the upper roller. In order to allow a removal of finished workpieces from the machine, the bearings of the upper roller have been made removable, e.g. foldable, in one or another way so that the workpiece can be drawn away axially from said upper roller. From a material-handling point of view but also for other reasons this construction suffers from several severe drawbacks, the most important perhaps that it requires a rather special and complicated form of drawing and hoisting handling device, such as a travelling crane, which furthermore often is rather space-consuming.

The main object of the present invention, therefore, is to provide a device in which the finished piece of sheet material which has become bent into :a more or less completely closed form around one of the rollers, i.e. the upper roller, can be removed from the machine in a simpler and faster way than hitherto known.

Another object of the invention also is to provide for a handling of non-treated as well as finished sheet workpieces by means of simpler and thus less expensive facilities and in an easier and more rational way.

A device according to the invention is substantially distinguished in that the roller around which the work-piece bends during the bending operation, particularly the upper roller, is journalled in the machine frame axially slidable so as to be drawn away or retracted completely out of the bending zone and thus provide for an easy and quick removal of the sheet work-piece bent into a more or less completely closed shape.

The invention will now be described further, by way of example only with reference to the accompanying drawings illustrating two embodiments thereof and in which:

FIGS. 1 and 2 are diagrammatic elevational views of a machine of the invention with the upper roller in operative and retracted position, respectively;

FIG. 3 is a perspective view of a machine with another embodiment of the support device for the upper roller.

With reference to the drawings and particularly FIGS. 1 and 2, a sheet bending machine according to the invention is provided with an upper roller 1 which is rotatably journalled although stationary in transverse direc- 3,490,260 Patented Jan. 20, 1970 tion and which co-operates with two rotatable lower rollers 5 which are transversely adjustable relatively to said stationary upper roller 1 so as to provide for a desired rounding or bending around said upper roller of a piece of sheet material (not illustrated) between said rollers I and 5. The bearings of the ends of the rollers are mounted in bearing supports 3 and 4 in the frame of the machine. In order to provide for a facilitated removal of a sheet workpiece which has been bent between said rollers into a more or less completely closed shape around the upper roller, the device according to the present invention is designed in such a way that the upper roller is journalled axially slidable and thus can be withdrawn completely or substantially out of the bending zone.

Although various constructive solutions of this retracting possibility of said upper roller are possible within the scope of the present invention, only a preferred embodiment with one type of roller support device and another embodiment with a slightly modified support device will be further described below.

In the first embodiment, in its end opposite the direction of removal the retractable upper roller 1 is journalled and releasably supported in the bearing support 3, and in its end facing the direction of removal said roller 1 is journalled in the bearing support 4 by a support device 2 which is adapted to keep said roller in proper alignment while in operative position. When retracting the upper roller 1, the remote end of said roller leaves the bearing support 3 and the roller 1 is slidably guided in a direction parallel to the axis of said roller only by means of the support device 2 carried by said machine frame.

In the embodiment illustrated in FIGS. 1 and 2, said support device 2 comprises rolls 6 travelling in rails 7 and is operated by a nut 8 travelling on a screw 9, which is driven by a motor 10. This embodiment is very effective and dependable but requires a rather great length of the machine frame in the longitudinal direction, about twice the length of the rollers.

Another embodiment, which is still more preferable in that it allows a much shorter frame of the machine is illustrated in FIG. 3. As shown, in this embodiment the support device comprises two lower rolls 11 and 12 on which the retractable roller 1 rests and which are rotatably mounted in the bearing support 4 on axes at right angles to the axis of said roller 1, and one upper roll 13 also rotatably mounted in said support 4 on an axis at right angles to the axis of the roller and engaging same from above at a point between said lower rolls 11 and 12. Preferably, said upper roll 13 is power-driven, e.g. by an electric motor 14 for retracting and replacing said roller 1. When retracting the upper roller 1, the same thus rides safely and rigidly on the lower rolls 11 and 12 while projecting out of said bearing support 4 in a cantilever manner, provided only that said rolls 11 and 12 are sufliciently spaced apart in the longitudinal direction of the roller 1.

An essential advantage with the device according to the present invention which cannot be obtained in machines of prior art is the feature that owing to the fact that the upper roller 1 can be completely removed from the bending zone, plane and non-treated sheet blanks can be delivered directly onto the lower rollers 5 by means .of a travelling crane or a truck. The upper roller 1 then can be moved back into the working position, after which the lower rollers 5 which are movable in transverse direction, are brought closer to the upper roller 1 so as to perform the desired bending action. After finishing the bending operation the upper roller 1 is again retracted, now out of the work-piece which is substantially closed therearound. For the final removal of the finished workpiece from the machine it is possible to use again the travelling crane or another lifting device, but mostly it is still easier if the operator rolls the work-piece away manually from the lowerrollers 5.

Other modifications can be made by those skilled in art without departing from the scope of the invention as defined in the accompanying claims.

I claim:

1. A sheet bending machine having a frame and at least two rotatable and co-operative rollers, preferably an upper roller and at least one lower roller for providing a round-bending of a sheet material work-piece introduced between said rollers, characterized in that the roller around which the work-piece bends into a substantially closed shape during the bending operation is journalled in the machine frame for axially slidable movement so as to be retracted completely out of the bending zone and thus provide for an easy and quick removal of the bent sheet material work-piece.

2. A machine according to claim 1, in which the retractable roller in its end facing the direction of axial withdrawal out of the bending zone, is jonrnalled in a support device, which is adapted to keep said roller in proper alignment while in operative position and provides for a longitudinal or axial movement of said roller.

3. A machine according to claim 2, in which said support device comprises two lower rolls on which the retractable roller rests and which are rotatably mounted in the machine frame on axes at right angles to the axis of said roller, and one upper roll also rotatably mounted in the frame on an axis at right angles to the axis of the retractable roller and engaging same from above at a point between said lower rolls, said upper roll, being power driven for retracting and replacing said roller.

4. A sheet bending machine having a frame and at least two rotatble and cooperative rollers, preferably an upper roller and at least one lower roller for eifeeting a round-bending of a sheet material work-piece introduced between said rollers, said work-piece being bent around said roller into a substantially closed configuration, said device comprising, means on said frame journalling said upper roller for movement along its own axis so as to be retracted completely out of the bending zone to provide for an easy, quick removal of the bent sheet material work-piece, said journalling means keeping said upper roller in proper alignment while in the operative position and providing for a longitudinal or axial movement of said upper roller thereafter, said journalling means further including two lower rolls on which the upper roller rests said rolls being rotatably mounted in the machine frame on axes on right angles to the axis of said upper roller, and one upper roll also rotatably mounted in the frame on an axis at right angles to the axis of the upper roller and engaging same from above at a point between said lower rolls, one of said rolls being power driven for retracting and replacing said upper roller.

References Cited UNITED STATES PATENTS 119,716 10/1871 Pomeroy 72-169 1,943,153 1/1934 Wirth 72160 2,432,666 12/1947 Isenberg et al 72175 X 3,208,260 9/1965 Sieger et al. 72-239 2,592,948 4/1952 Peterson 72-165 MILTON S. MEHR, Primary Examiner US. Cl. X.R. 

